1. Field of the Invention
The present invention relates to improvements of a radio-frequency receiver device including an adaptive processing portion operable to control weights to be given to respective received signals respectively received by a plurality of antenna elements.
2. Description of the Related Art
In various fields of communication, there are available adaptive processing techniques for controlling the weights to be given to respective received signals respectively received by a plurality of antenna elements. In the field of a mobile communication system such as a PHS (Personal Handyphone System), for example, there have been proposed techniques for improving the sensitivity of reception of the received signals in a radio-frequency receiver device including an adaptive processing portion operable to control the weights to be respectively given to the received signals respectively received by a plurality of antenna elements. US 2004/0246889 A1 corresponding to JP-2003-124857 A discloses an example of such a radio-frequency receiver device. The radio-frequency receiver device disclosed in this publication is arranged to converge the weights such that signals generated by the adaptive processing portion become as close as possible to reference signals.
However, the adaptive processing according to the conventional technique described above requires not only the use of training signals for comparison with the reference signals, and transmission of the training signals in addition to desired data to be transmitted, but also a considerably time until the weights have been converged. Thus, there has been a need of developing a radio-frequency receiver device including an adaptive processing portion which is capable of converging the weights as quickly as possible.